I'd like to calculate portfolio allocation beta on a portfolio that has different asset classes. The portfolio may be made up of:
Short term bond fund (with beta tied to Barclays U.S. Aggregate Bond Index) Sector fund 1 (with beta tied to DOW) SP500 fund (with beta tied to SP500 index)
I understand how to calculate portfolio beta if all assets are benchmarked off the same index but not when beta is heterogenous. Can anyone provide a formula(s) of how it is calculate along with some simple examples?